Radiation Image Processing System And Radiation Image Processing Apparatus

ABSTRACT

A radiation image processing system, including: an image analysis section which performs image analysis to a plurality of frame images that is obtained by moving image imaging of a target site having periodicity in a movement or frame images that are obtained after image processing based on the frame images obtained by the moving image imaging and which determines a period of the movement; and a reproduction range setting section which sets a range of frame images to be reproduced and displayed among the frame images based on an analysis result of the period determined by the image analysis section.

CROSS-REFERENCE TO RELATED APPLICATIONS

The entire disclosure of Japanese Patent Application No. 2016-121341filed on Jun. 20, 2016 including description, claims, drawings andabstract are incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a radiation image processing system anda radiation image processing apparatus.

2. Description of Related Art

Attempts have been made to use semiconductor image sensors such as FPDs(flat panel detectors) for performing dynamic imaging (imaging ofdynamic states) at sites which are diagnosis targets (hereinafter,referred to as target sites) and use the obtained results for diagnosisinstead of capturing and diagnosing still images of radiation (X-ray)using conventional films/screens and stimulable phosphor plates.

Specifically, by using rapid responsiveness of a semiconductor imagesensor in reading and deleting image data, pulsed radiation iscontinuously emitted from a radiation source at the reading and deletingtimings of the semiconductor image sensor, and imaging is performed aplurality of times per second to capture a dynamic state at a targetsite. By sequentially displaying a series of frame images obtained bythe dynamic imaging, a doctor can observe a series of movements at thetarget site.

For example, in a case where the target site is a lung or a heart, thedoctor can observe and diagnose the point where a lung function(ventilation function, pulmonary blood flow function or the like) islowered, the point where heartbeat of the heart is abnormal or the likeby watching the manner of movement of the lung or the heart which isreproduced on a screen, that is, watching each of the frame images (seeFIG. 11, for example) obtained by dynamic imaging of the lung or theheart (see Japanese Patent Application Laid Open Publication No.2012-5729, for example).

When moving image reproduction is performed for a plurality of frameimages which is obtained by dynamic imaging, in some cases, loopreproduction is performed for the frame images (that is, the movingimage is repeatedly reproduced by restarting the moving imagereproduction from the first frame image immediately and continuouslyafter the end of display of the last frame image).

At that time, in a case where the target site is a lung of a patient,for example, the lung state of the patient does not change from aresting inspiratory phase to a resting expiratory phase in a moment ifthe last frame image and the first frame image show entirely differentlung states (for example, a resting inspiratory phase and a restingexpiratory phase). Thus, the doctor watching the change can recognizethat the moving image reproduction of a series of frame images ended andthe next moving image reproduction is newly started at the moment whenthe lung state is switched from the resting inspiratory phase to theresting expiratory phase.

As shown in FIG. 11, in a case where both of the last frame image andthe first frame image show the resting inspiratory phases of the lung,for example, when loop reproduction is performed for the plurality offrame images, the moving image reproduction is ended at the restinginspiratory phase and the next moving image reproduction is immediatelystarted at the resting inspiratory phase. Thus, each of the frame imagesis reproduced as if the patient naturally continues the breathing.

The resting inspiratory phase and the resting expiratory phaserespectively indicate the state in which the patient breathes in to makethe lung maximum and the state in which the patient breathes out to makethe lung minimum when the patient performs breathing in a resting state.The maximum inspiratory phase and the maximum expiratory phaserespectively indicate the state in which the patient fully breathes into make the lung maximum and the state in which the patient fullybreathes out to make the lung minimum.

However, in a case where the lung states captured in the last frameimage and the first frame image are similar to each other, for example,when loop reproduction is performed for the plurality of frame images,the lung which has been naturally moving moves discontinuously and, forexample, appears to twitch unnaturally in some cases at the time whenthe moving image reproduction is finished and the next moving imagereproduction is immediately started.

In such a case, the doctor watching this possibly experiences a feelingof strangeness or possibly misunderstands that the patient has a diseaseor an abnormality, which decreases the accuracy of diagnosis or leads towrong diagnosis. When a plurality of frame images obtained by dynamicimaging of a target site having periodicity in a movement of a lung, aheart or the like is reproduced, it is necessary to reproduce the frameimages so that the user such as a doctor does not experience a feelingof strangeness, the accuracy of diagnosis by the doctor is not decreasedand the wrong diagnosis is not generated.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the aboveproblems and an object of the present invention is to provide aradiation image processing system and a radiation image processingapparatus capable of preventing a user from experiencing the feeling ofstrangeness, decrease in the accuracy of diagnosis and generation ofwrong diagnosis at the time of reproducing a plurality of frame imagesobtained by moving image imaging of a target site which has periodicityin a movement.

In order to solve at least one of the above problems, according to oneaspect of a preferred embodiment of the present invention, there isprovided a radiation image processing system, including: an imageanalysis section which performs image analysis to a plurality of frameimages that is obtained by moving image imaging of a target site havingperiodicity in a movement or frame images that are obtained after imageprocessing based on the frame images obtained by the moving imageimaging and which determines a period of the movement; and areproduction range setting section which sets a range of frame images tobe reproduced and displayed among the frame images based on an analysisresult of the period determined by the image analysis section.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, advantages and features of the presentinvention will become more fully understood from the detaileddescription given hereinafter and the appended drawings which are givenby way of illustration only, and thus are not intended as a definitionof the limits of the present invention, and wherein:

FIG. 1 is a block diagram showing a configuration of a radiation imageprocessing apparatus or a radiation image processing system in anembodiment;

FIG. 2 is a view showing a frame image obtained by extracting a signalcomponent of a pulmonary blood flow as an example of each of the frameimages obtained after image processing;

FIG. 3A is a view showing positions of a lung apex and such like in eachof the frame images;

FIG. 3B is a view showing positions of a heart wall and such like ineach of the frame images;

FIG. 4A is a view showing a width, a height and such like of a lung ineach of the frame images;

FIG. 4B is a view showing a width, a height and such like of a heart ineach of the frame images;

FIG. 5A is a view showing target regions set at positions of a lung apexand such like in each of the frame images;

FIG. 5B is a view showing target regions set at positions of a heart andsuch like in each of the frame images;

FIG. 6A is a graph plotting a height of a lung as an example of amorphology value;

FIG. 6B is a graph for explaining that a frame image having a sameheight of a lung L as the height of the lung L in a head frame is set asan end frame;

FIG. 7 is a graph showing an example of a change speed of the morphologyvalue and for explaining how to set the end frame;

FIG. 8 is a view for explaining that a frame image having a morphologyvalue and a change speed of the morphology value which are both same asthose of the head frame is set as an end frame;

FIG. 9 is a view showing reproduction and display of each of the frameimages in a set range on a display section and display showing how manyperiods correspond to the range which is under loop reproduction;

FIG. 10 is a view showing display of a seek bar near the frame imagewhich is under loop reproduction or the like; and

FIG. 11 is a view showing an example of each of the frame imagesobtained by dynamic imaging of a chest of a subject.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, an embodiment of a radiation image processing system and aradiation image processing apparatus according to the present inventionwill be described with reference to the drawings.

Hereinafter, description will be made for a case where after-mentionedimage analysis section and reproduction range setting section areconfigured in a single apparatus (that is, a case where the radiationimage processing apparatus includes the image analysis section and thereproduction range setting section). However, for example, though notshown in the drawings, it is also possible to configure at least theimage analysis section and the reproduction range setting section asseparate apparatuses and connect the apparatuses via a network or thelike to configure a system (that is, as the radiation image processingsystem).

Hereinafter, description will be made for a case where a display sectionis formed integrally with the image analysis section and thereproduction range setting section. However, though not shown in thedrawings, it is also possible to configure the display section separatefrom the image analysis section and the reproduction range settingsection and connect the sections via a network or the like to configurea system (that is, as the radiation image processing system).

[Configuration of Radiation Image Processing Apparatus (Radiation ImageProcessing System)]

The configuration of a radiation image processing apparatus 1 (orradiation image processing system 1, hereinafter, the same applies) inthe embodiment will be described. FIG. 1 is a block diagram showing theconfiguration of a radiation image processing apparatus in theembodiment. In the embodiment, as shown in FIG. 1, the radiation imageprocessing apparatus 1 is configured by including a general-purposecomputer in which a CPU (Central Processing Unit) 10, a ROM (Read OnlyMemory) 11, a RAM (Random Access Memory) 12, an input output interface13 and such like are connected to a bus. The radiation image processingapparatus 1 is connected to a network N via the input output interface13.

Furthermore, the CPU 10 is connected to an input section 14 which isconfigured by including a keyboard, a mouse, a touch panel and suchlike, a display section 15 which is configured by including a CRT(Cathode Ray Tube), an LCD (Liquid Crystal Display) or the like, andsuch like. The CPU 10 is also connected to a storage section 16 which isconfigured by including a non-volatile semiconductor memory, an HDD(Hard Disk Drive) or the like.

The radiation image processing apparatus 1 can also be configured as adedicated apparatus, not as a general-purpose computer as describedabove. Though not shown in the drawings, it is also possible to have aconfiguration including an image capturing apparatus which performsdynamic imaging, a control apparatus such as a console which controlsthe image capturing, an image storage database for storing a pluralityof frame images which were captured and such like via a network N inaddition to the radiation image processing apparatus 1.

In the embodiment, the CPU 10 of the radiation image processingapparatus 1 is configured to function as the image analysis section andthe reproduction range setting section according to the presentinvention, and the display section 15 is configured to function as thedisplay section according to the present invention. Hereinafter, theimage analysis section 10, the reproduction range setting section 10 andthe display section 15 will be described.

[Configuration of Image Analysis Section]

Hereinafter, description will be made first for the configuration of theimage analysis section 10, that is, processing which is performed in theimage analysis section 10. In the embodiment, the image analysis section10 performs image analysis to each of a plurality of frame images Pobtained by moving image imaging of a target site having periodicity ina movement and determines the period τ of the movement. As the methodfor determining the movement period τ by the image analysis section 10,there can be adopted methods described in International Publication No.2009/090894, Japanese Patent Application Laid Open Publication No.2009-273671 and Japanese Patent Application Laid Open Publication No.2009-153678, for example.

At that time, a plurality of frame images P which is a target of theimage analysis may be obtained by moving image imaging of a target sitehaving periodicity in a movement as described above. That is, forexample, the frame images P may be obtained by dynamic imaging of alung, a heart or the like as shown in FIG. 11 (in such a way, dynamicimaging is included in moving image imaging), and though not shown inthe drawings, the frame images P may be frame images obtained by movingimage imaging capturing a manner in which the patient periodically movesa hand, a leg, a neck, a body or the like (that is, wrist joint, anklejoint, shoulder joint, hip joint or the like) by bending, stretching andtwisting, for example.

Furthermore, the plurality of frame images P which is a target of theimage analysis may be frame images P obtained after image processingsuch as frame images P (see FIG. 2) obtained by extracting signalcomponents of pulmonary blood flow (blood flow signal components) on thebasis of the frame images obtained by dynamic imaging of a lung of apatient as shown in FIG. 2, for example.

In the embodiment, the image analysis section 10 calculates a morphologyvalue α of a body part such as a lung, a heart or the like captured ineach of the frame images P and a change speed Δα of the morphology valueα.

The image analysis section 10 can be configured to calculate any ofpositions in each of the frame images P of a lung apex, a diaphragm, arib, a clavicle, a thorax, a shoulder, an arm, an abdomen, a heart walland an aortic arch as shown in FIGS. 3A and 3B, a width xl, a height yland an area sl in each of the frame images P of a lung L as shown inFIG. 4A and a width xh, a height yh and an area sh in each of the frameimages P of a heart H as shown in FIG. 4B. As the change speed Δα of themorphology value α, for example, any of change speeds Δα of theabove-mentioned morphology values α can be calculated.

In the embodiment, the image analysis section 10 sets a target regionROI in each of the frame images P as shown in FIGS. 5A and 5B andcalculates a density value β or the change speed Δβ of the density valueβ of each pixel in the target region ROI. Though FIGS. 5A and 5B showcases of setting rectangular target regions ROI on a frame image P, thetarget region ROI may be a polygon, a circle, an ellipse or the like,for example, and the shape of the target region ROI is not limited.

As the density value β, the image analysis section 10 can calculate ananalysis value (any of average value, median value, mode value,integration value, minimum value and maximum value) of a density value βof each pixel in the target region ROI including a part of any of thelung apex, diaphragm, rib, clavicle, thorax, shoulder, arm, abdomen,heart, alveolus, bronchus, pulmonary artery and aortic arch captured ineach of the frame images P.

As the change speed Δβ of the density value β, the change speed of theanalysis value of the above density value β can be calculated.Hereinafter, in the embodiment, the density value β and the change speedΔβ of the density value β respectively represent the analysis value ofthe above density value β and the change speed of the analysis value ofthe density value β.

[Configuration of Reproduction Range Setting Section]

Next, the configuration of the reproduction range setting section 10,that is, processing performed in the reproduction range setting section10 will be described. Hereinafter, the function of the radiation imageprocessing apparatus 1 or the radiation image processing system 1 in theembodiment will be described together.

The reproduction range setting section 10 sets the range of frame imagesP to be reproduced and displayed on the display section 15 among theframe images P on the basis of the analysis result of the period τdetermined by the image analysis section 10.

In the embodiment, the reproduction range setting section 10 sets therange of frame images P to be reproduced and displayed among theplurality of frame images P, which were obtained by moving imageimaging, by setting a head frame image Pin in the range (that is, theframe image Pin to be displayed first in the reproduction display,hereinafter, simply referred to as a head frame Pin) and an end frameimage Pfi in the range (that is, frame image Pfi to be displayed last inthe reproduction display, hereinafter, simply referred to as an endframe Pfi).

Hereinafter, setting processing of the range of frame images P to bereproduced and displayed by the reproduction range setting section 10will be specifically described. FIG. 6A is a graph obtained by plottingwith the longitudinal axis of the height y (see FIG. 4A) in each of theframe images P of the lung L as an example of the morphology value α anda horizontal axis of a frame number n (n≧1) of each of the frame imagesP. The τ in FIG. 6A represents a period of breathing.

In a case where the target site is a lung L in such a way, since thedoctor cannot perform diagnosis and such like by watching the dynamicstate of the lung L unless the frame images P are reproduced for thenumber of frames of one period or more of the breathing. Thus, thereproduction range setting section 10 sets the range of reproduction anddisplay by targeting the frame images P including at least one period ofbreathing.

Though not shown in the drawings, in a case where the target site is aheart H (see FIG. 4B and others), for example, the graph of morphologyvalue α regarding the heart H is a graph having periodicity similarly toFIG. 6A. However, the doctor cannot perform diagnosis and such like bywatching the dynamic state of the heart H unless the frame images P arereproduced for the number of frames of one period or more of theheartbeat similarly to the case of lung L. Thus, the reproduction rangesetting section 10 sets the range of reproduction and display bytargeting frame images P including at least one period of heartbeat. Thesame also applies to a case of setting the range of reproduction anddisplay targeting frame images P obtained after image processing asillustrated in FIG. 2.

In the embodiment, the reproduction range setting section 10 sets theabove range so that the breathing phase (heartbeat phase in a case wherethe target site is the heart H, the same applies, hereinafter) of thehead frame Pin in the range nearly matches the breathing phase of theend frame Pfi in the range in the graph shown in FIG. 6A, for example.

[Range Setting Method 1]

At that time, as shown in FIG. 6B, for example, when the point A in thegraph is selected as the head frame Pin of the reproduction displayrange, since the morphology value α is the height y of the lung L inthis case, the range can be set by setting a frame image P having aheight y of lung L which is same or nearly same as the height y of lungL in the head frame Pin as the end frame Pfi in the range. There arecases where a plurality of end frames Pfi can be set as in a case ofFIG. 6B.

[Range Setting Method 2]

The range can be set by setting the head frame Pin of the reproductiondisplay range and the end frame Pfi in the range also on the basis ofthe above-mentioned change speed Δα of the morphology value α (that is,change speed Δy of the height y of the lung L which is the morphologyvalue α in the embodiment).

For example, in a case where the morphology value α changes for each ofthe frame images P as shown in FIG. 6A, FIG. 7 is obtained by plottingthe change speeds Δα of the morphology values α (Δy in the aboveexample, that is, the difference between α(y) in a target frame P andα(y) in the previous frame P) for frame numbers n of respective frameimages P.

As shown in FIG. 7, when the point A in the graph is selected as thehead frame Pin in the reproduction display range, the range can be setby setting, as the end frame Pfi in the range, the frame image P havingthe same or nearly same change speed Δα of the morphology value α as thechange speed Δα (that is, Δy) of the morphology value α in the headframe Pin. Also in this case, there are cases where a plurality of endframes Pfi can be set as shown in FIG. 7.

[Range Setting Method 3]

As described above, the range of frame images P to be reproduced anddisplayed can be set by setting the head frame Pin and the end frame Pfionly on the basis of the morphology value α or only on the basis of thechange speed Δα of the morphology value α. However, as shown in FIG. 8,for example, the above range can be set by setting, as the end frame Pfiof the reproduction display range, the frame image P having the same ornearly same morphology value α as the morphology value α (that is, y inthe above example) in the head frame Pin and having the same or nearlysame change speed Δα of the morphology value α as change speed Δα (thatis, Δy in the above example) of the morphology value α in the head framePin.

In this case, as the end frame Pfi, there is set a frame image P havingthe same or nearly same height y (that is, morphology value α) of thelung L as the height y of lung L in the head frame Pin and having thesame or nearly same change speed (that is, change speed of themorphology value α) of the height y of the lung L. That is, as shown inFIG. 8, for example, as the end frame Pfi, there is set a frame image Pcapturing the lung L starting to increase the height y similarly to thehead frame Pin capturing the lung L starting to increase the height y.

Thus, by such a configuration, it is possible to set the end frame Pfiwith more accuracy and accurately set, as the end frame Pfi in the rangewhen reproducing and displaying a plurality of frame images P obtainedby moving image imaging of a target site having periodicity in amovement, the frame image P in which the target site moves (expansion,deflation or the like) similarly to the head frame Pin (the morphologyof target site is changing similarly).

For example, when loop reproduction is performed for frame images P inthe range, the movements of lung L are displayed so as to be naturallyconnected even if the head frame Pin is reproduced following the endframe Pfi. Thus, it is possible to reproduce (loop reproduction) theframe images P accurately without making the user such as a doctorexperience a feeling of strangeness, decreasing the accuracy indiagnosis or generating wrong diagnosis when reproduction or loopreproduction is performed for the frame images P.

Though the above description is made for a case where the target site isa lung L, the same configuration is also possible for cases where thetarget site is a heart H, a hand, a leg, a neck and such like. Thoughthe above description is made for a case where the reproduction rangesetting section 10 sets the range of frame images P to be reproduced anddisplayed on the basis of the morphology value α and/or the change speedΔα of the morphology value α, the same configuration as the aboveconfiguration is also possible for a case where the reproduction rangesetting section 10 sets the range of frame images P to be reproduced anddisplayed on the basis of the above-mentioned density value β and/or thechange speed of the density value β.

Furthermore, even when the frame images P are the frame images Pobtained after image processing as shown in FIG. 2, the sameconfiguration is possible as long as the frame images P obtained afterimage processing are regarding a target site having periodicity in amovement.

[Processing in a Case where there is a Plurality of Candidates for FrameImage P to be Set]

As described above, in a case where the head frame Pin is selected, thereproduction range setting section 10 automatically sets the end framePfi and sets the range of frame images P to be reproduced and displayed.However, though the description is omitted, in a case where the endframe Pfi is selected, the reproduction range setting section 10similarly automatically sets the head frame Pin and sets the range offrame images P to be reproduced and displayed.

At that time, as shown in FIG. 8, for example, in a case where there area plurality of candidates for the end frame Pfi, when the end frame Pfi(end frame fi in the left side in FIG. 8) which was captured earlier isset as the end frame Pfi, the frame images P for the amount of oneperiod from the head frame Pin to the end frame Pfi are reproduced anddisplayed when frame images P are reproduced and displayed.

In this case, when the end frame Pfi (end frame fi in the right side inFIG. 8) which was captured later is set, for example, the frame images Pfor the amount of two periods from the head frame Pin to the end framePfi are reproduced and displayed when frame images P are reproduced anddisplayed.

The reproduction display (loop reproduction) of frame image P isperformed for a doctor to see the frame images P and determine whetherthe patient has abnormality or a disease at the target site as describedabove, and the abnormality and the disease are possibly captured clearlyin a later period. Thus, the range of frame images P to be reproducedand displayed may be a range including as many periods τ as possible.

Thus, in a case where there is a plurality of candidates for the endframe Pfi in the range of frame images P to be reproduced and displayed,it is preferable that the reproduction range setting section 10 sets theend frame Pfi which was captured later as the end frame Pfi in therange.

When the end frame Pfi is selected, in a case where there is a pluralityof candidates for the head frame Pin in the range of frame images P tobe reproduced and displayed, it is preferable that the reproductionrange setting section 10 sets the head frame Pin which was capturedearlier as the head frame Pin in the range for the same reason as theabove case.

[How to Select Head Frame Pin and End Frame Pfi]

In the embodiment, as described above, when the head frame Pin or theend frame Pfi is selected, the reproduction range setting section 10sets the end frame Pfi or the head frame Pin as described above and setsthe range of frame images P to be reproduced and displayed.

The head frame Pin and the end frame Pfi may be selected by a doctor, aradiologist or the like who is a user selecting arbitrary one of theplurality of frame images P, and may be selected on a graph such asFIGS. 6B, 7 and 8, for example. For example, in a case where the targetsite is the lung L, the reproduction range setting section 10 maydisplay “resting inspiratory phase (maximum inspiratory phase)”,“resting expiratory phase (maximum expiratory phase)”, “intermediatephase” and such like on the display section 15 so that the user selectsone of them.

The reproduction range setting section 10 may automatically select aframe image P at the resting inspiratory phase or the resting expiratoryphase or an arbitrary frame image P. At that time, for example, thereproduction range setting section 10 may refer to the disease of thepatient to automatically select the head frame Pin and the end framePfi.

That is, though the same also applies to a case of selecting by a user,for example, in a case where the disease of patient is a restrictivedisease such as pneumonia and pulmonary fibrosis, emphysema, atelectasisor the like, since the ability to take air into lungs is decreased,there may be selected, as the head frame Pin or the end frame Pfi, aframe image P at or near the phase from which air is taken into thelungs such as the resting expiratory phase (for example, see FIG. 11)and maximum expiratory phase.

By such a configuration, since the frame images P are reproduced (loopreproduction) from a phase from which the air is taken into lungs of thepatient, the doctor easily evaluates the ventilation function such asthe difficulty in taking air into lungs by watching the reproduced frameimages P.

Also, for example, in a case where the disease of patient is anobstructive disease such as asthma and chronic obstructive pulmonarydisease (COPD), since the ability to take air out from lungs isdecreased, there may be selected, as the head frame Pin or the end framePfi, a frame image P at or near the phase from which air is taken outfrom the lungs such as the resting inspiratory phase (for example, seeFIG. 11) and maximum inspiratory phase.

By such a configuration, since the frame images P are reproduced (loopreproduction) from a phase from which the air is taken out from lungs ofthe patient, the doctor easily evaluates the ventilation function suchas the difficulty in taking air out from lungs by watching thereproduced frame images P.

[Reproduction and Display on Display Section]

In the embodiment, the frame images P in the range (that is, from thehead frame Pin to the end frame Pfi) which was set by the reproductionrange setting section 10 as described above are reproduced and displayedon the display section 15 as shown in FIG. 9. As mentioned above, thedisplay section 15 may be separately configured from the image analysissection 10 and the reproduction range setting section 10.

Though each of the frame images P may be displayed once on the displaysection 15 from the head frame Pin to the end frame Pfi, the frameimages P from the head frame Pin to the end frame Pfi may be reproducedby loop reproduction to be displayed.

By such a configuration, loop reproduction is performed to frame imagesP in a state in which the end frame Pfi of a loop and the head frame Pinof the next loop are smoothly connected to each other. This avoids thestate in which the lung L or the like which is being reproduced anddisplayed appears to discontinuously move and unnaturally twitch. Thus,loop reproduction can be performed in a state in which the lung Lnaturally moves.

In a case where the lung L or the like unnaturally moves due to adisease or the like, the unnatural movement is truly reproduced in theembodiment. That is, the radiation image processing system 1 or theradiation image processing apparatus 1 in the embodiment prevents thetarget site from moving unnaturally at the connection part of frameswhen performing loop reproduction by connecting the end frame Pfi of aloop to the head frame Pin of the next loop. In a case where the targetsite has an unnatural movement due to a disease or the like, theradiation image processing system 1 or the radiation image processingapparatus 1 in the embodiment does not remove the unnatural movementwhen performing reproduction and display.

In the embodiment, since the end frame Pfi of a loop is naturallyconnected to the head frame Pin of the next loop as described above, thedoctor or the like watching it possibly loses the number of periods offrame images P under loop reproduction and repeated display.

Thus, as shown in FIG. 9, for example, the display section 15 maydisplay the number of periods corresponding to the range under loopreproduction by displaying, for example, “under loop playback of frameimages for two periods” simultaneously with reproduction of the frameimages P. By such a configuration, the doctor or the like can accuratelyrecognize the number of periods of frame images P under loopreproduction and repeated display.

[Effect]

As described above, according to the radiation image processing system 1and the radiation image processing apparatus 1 in the embodiment, theimage analysis section 10 performs image analysis to a plurality offrame images P (or frame images P (see FIG. 2) obtained after imageprocessing based on the plurality of frame images P) obtained by movingimage imaging of a target site having periodicity in a movement, and thereproduction range setting section 10 sets the range of frame image P tobe reproduced and displayed among the frame images P on the basis of theanalysis result of period T determined by the image analysis section 10.

When a plurality of frame images P obtained by moving image imaging of atarget site (lung L, heart H, hand, leg, neck or the like) havingperiodicity in a movement is reproduced, the movements of the targetsite are displayed so as to be connected to each other naturally andsmoothly. Thus, when the frame images P are reproduced or loopreproduction is performed for the frame images P, the user such as adoctor does not experience a feeling of strangeness, the accuracy ofdiagnosis is not decreased and wrong diagnosis is not generated, andthus, the frame images P can be accurately reproduced (loop reproductioncan be accurately performed).

Modification Examples

In the embodiment, as described above, the image analysis section 10 andthe reproduction range setting section 10 read out a plurality of frameimages P obtained by moving image imaging from an image storage databaseor the like, once store the frame images P in the storage section 16(see FIG. 1) or the like and perform the above processing. After thehead frame Pin and the end frame Pfi are set as described above, theframe images P before the head frame Pin and frame images P after theend frame Pfi are not necessary.

Thus, after the head frame Pin and the end frame Pfi are set asdescribed above, the frame images P before the head frame Pin and frameimages P after the end frame Pfi may be deleted from the storage section16 and removed from the target of processing. By such a configuration,unnecessary frame images P are deleted and the data amount can bereduced.

In a case where the frame rate of moving image imaging is less than 10fps (especially less than 5 fps), when the frame images P are reproducedand displayed, the frame images P are reproduced as in frame advance,and the target site does not appear to smoothly move. Thus, when loopreproduction is performed for such frame images P, for example, thetarget site such as lung L and heart H appears to twitch ordiscontinuously move each time the frame is switched. Thus, the doctoror the like does not experience a feeling of strangeness since he/shesees the moving image as such.

Thus, there may be a configuration of not applying the present inventionto frame images of such a moving image, that is, a moving image capturedat a frame rate of less than 10 fps (or less than 5 fps). There is nosense in applying the present invention to such frame images P since themovements of the target site are not smoothly connected to each otherbetween the end frame Pfi and the head frame Pin of the next loop. Bysuch a configuration, the burden on the reproduction range settingsection 10 and such like can be reduced for the amount of reducedwasteful processing.

Furthermore, the image analysis section 10, the reproduction rangesetting section 10 and such like may perform the above processing onlywhen instructed by a doctor or the like who is a user. By such aconfiguration, the burden on the reproduction range setting section 10and such like can be reduced.

Along with the above embodiment, or independently from the aboveembodiment, the following configuration, for example, may be alsoapplied for making the user such as a doctor recognize that that theloop reproduction returned to a first frame image P of the loop whenloop reproduction is performed for frame images P. In a case where thefollowing configuration is applied to the embodiment, the “first frameimage P of the loop” and the “last frame image P of the loop” in thefollowing description respectively indicate the above “head frame Pin”and “end frame Pfi”. However, in a case where the followingconfiguration is applied independently from the embodiment, the “firstframe image P of the loop” and the “last frame image P of the loop” inthe following description may not necessarily be the above “head framePin” and the “end frame Pfi”.

For example, when loop reproduction is performed for the frame images Pin a range on the display section 15, the portion around the frame imageP is displayed so as to be colored, and the color around the frame imageP gradually changes as the frame image P to be displayed is switchedfrom the first frame image P of the loop to the last frame image P ofthe loop. By setting the first frame image P of the loop and the lastframe image P of the loop to have entirely different colors (colors notsimilar to each other), when the loop reproduction is performed, thecolor around the frame image P changes to an entirely different color atthe time when the loop reproduction returns to the first frame image Pof the loop. Thus, the user can recognize that the loop reproductionreturned to the first frame image P of the loop.

After the last frame image P of a loop is displayed, sound may be madeat the time when the first frame image P of the next loop is displayed.Furthermore, a progress bar may be displayed near the frame image Punder loop reproduction or a seek bar B may be displayed as shown inFIG. 10. At that time, the color, size and such like of a slider S maybe changed in accordance with the progress of loop reproduction.

Furthermore, after the last frame image P of a loop is displayed, at thetime when the first frame image P of the next loop is displayed, aninterval (temporary stop, decrease in reproduction speed or the like)may be provided in loop reproduction. By such a configuration, the usercan surely recognize that the loop reproduction returned to the firstframe image P of the loop.

The present invention is not limited to the above embodiment,modification examples and such like, and changes can be appropriatelymade within the scope of the present invention.

What is claimed is:
 1. A radiation image processing system, comprising:an image analysis section which performs image analysis to a pluralityof frame images that is obtained by moving image imaging of a targetsite having periodicity in a movement or frame images that are obtainedafter image processing based on the frame images obtained by the movingimage imaging and which determines a period of the movement; and areproduction range setting section which sets a range of frame images tobe reproduced and displayed among the frame images based on an analysisresult of the period determined by the image analysis section.
 2. Theradiation image processing system according to claim 1, wherein thereproduction range setting section sets the range so that the range is arange of frame images which are obtained by dynamic imaging of a chestof a subject or frame images which are obtained after image processingbased on the frame images obtained by the dynamic imaging, the rangeincludes at least one period of breathing, and a breathing phase of ahead frame image in the range nearly matches a breathing phase of an endframe image in the range.
 3. The radiation image processing systemaccording to claim 1, wherein the reproduction range setting sectionsets the range so that the range is a range of frame images which areobtained by dynamic imaging of a chest of a subject or frame imageswhich are obtained after image processing based on the frame imagesobtained by the dynamic imaging, the range includes at least one periodof heartbeat, and a heartbeat phase of a head frame image in the rangenearly matches a heartbeat phase of an end frame image in the range. 4.The radiation image processing system according to claim 2, wherein whenthere is a plurality of candidates for the end frame image in the range,the reproduction range setting section sets a frame image which iscaptured later to be the end frame image in the range, and when there isa plurality of candidates for the head frame image in the range, thereproduction range setting section sets a frame image which is capturedearlier to be the head frame image in the range.
 5. The radiation imageprocessing system according to claim 2, wherein the reproduction rangesetting section sets the head frame image in the range and the end frameimage in the range based on a morphology value of a body part capturedin each of the frame images, a change speed of the morphology value orboth of the morphology value and the change speed of the morphologyvalue.
 6. The radiation image processing system according to claim 5,wherein the morphology value is any of positions of a lung apex, adiaphragm, a rib, a clavicle, a thorax, a shoulder, an arm, an abdomen,a heart wall and an aortic arch in each of the frame images, a width, aheight and an area of a lung in each of the frame images, and a width, aheight and an area of a heart in each of the frame images.
 7. Theradiation image processing system according to claim 5, wherein thechange speed of the morphology value is any of change speeds ofpositions of a lung apex, a diaphragm, a rib, a clavicle, a thorax, ashoulder, an arm, an abdomen, a heart wall and an aortic arch in each ofthe frame images, a change speed of a width, a change speed of a heightand a change speed of an area of a lung in each of the frame images, anda change speed of a width, a change speed of a height and a change speedof an area of a heart in each of the frame images.
 8. The radiationimage processing system according to claim 2, wherein the reproductionrange setting section sets the head frame image in the range and the endframe image in the range based on a density value of a pixel in each ofthe frame images, a change speed of the density value or both of thedensity value and the change speed of the density value.
 9. Theradiation image processing system according to claim 8, wherein thedensity value is an analysis value of a density value of each pixel in atarget region which includes a part of any of a lung apex, a diaphragm,a rib, a clavicle, a thorax, a shoulder, an arm, an abdomen, a heart, analveolus, a bronchus, a pulmonary artery and an aortic arch captured ineach of the frame images.
 10. The radiation image processing systemaccording to claim 8, wherein the change speed of the density value is achange speed of an analysis value of a density value of each pixel in atarget region which includes a part of any of a lung apex, a diaphragm,a rib, a clavicle, a thorax, a shoulder, an arm, an abdomen, a heart, analveolus, a bronchus, a pulmonary artery and an aortic arch captured ineach of the frame images.
 11. The radiation image processing systemaccording to claim 9, wherein the analysis value is any of an averagevalue, a median value, a mode value, an integration value, a minimumvalue and a maximum value of the density value of each pixel in thetarget region.
 12. The radiation image processing system according toclaim 1, further comprising a display section which displays the frameimages in the range set by the reproduction range setting section byreproducing the frame images.
 13. The radiation image processing systemaccording to claim 12, wherein the display section displays the frameimages in the range by performing loop reproduction of the frame images.14. The radiation image processing system according to claim 13, whereinthe display section displays a number of periods corresponding to therange simultaneously with reproduction of the frame images.
 15. Aradiation image processing apparatus, comprising: an image analysissection which performs image analysis to a plurality of frame imagesthat is obtained by moving image imaging of a target site havingperiodicity in a movement or frame images that are obtained after imageprocessing based on the frame images obtained by the moving imageimaging and which determines a period of the movement; and areproduction range setting section which sets a range of frame images tobe reproduced and displayed among the frame images based on an analysisresult of the period determined by the image analysis section.